/*
NPlot - A charting library for .NET

ImagePlot.cs
Copyright (C) 2003-2004
Matt Howlett

Redistribution and use of NPlot or parts there-of in source and
binary forms, with or without modification, are permitted provided
that the following conditions are met:

1. Re-distributions in source form must retain at the head of each
   source file the above copyright notice, this list of conditions
   and the following disclaimer.

2. Any product ("the product") that makes use NPlot or parts 
   there-of must either:
  
    (a) allow any user of the product to obtain a complete machine-
        readable copy of the corresponding source code for the 
        product and the version of NPlot used for a charge no more
        than your cost of physically performing source distribution,
	on a medium customarily used for software interchange, or:

    (b) reproduce the following text in the documentation, about 
        box or other materials intended to be read by human users
        of the product that is provided to every human user of the
        product: 
   
              "This product includes software developed as 
              part of the NPlot library project available 
              from: http://www.nplot.com/" 

        The words "This product" may optionally be replace with 
        the actual name of the product.

------------------------------------------------------------------------

THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

*/

using System;
using System.Drawing;
using System.Drawing.Drawing2D;

namespace NPlot
{

	/// <summary>
	/// Encapsulates functionality for plotting data as a 2D image chart.
	/// </summary>
	public class ImagePlot : IPlot
	{
		private double[,] data_;
		private double xStart_ = 0.0;
		private double xStep_ = 1.0;
		private double yStart_ = 0.0;
		private double yStep_ = 1.0;
		

		/// <summary>
		/// At or below which value a minimum gradient color should be used.
		/// </summary>
		public double DataMin      
		{
			get          
			{
				return dataMin_;
			}
			set            
			{
				dataMin_ = value;
			}
		}
		private double dataMin_;


		/// <summary>
		/// At or above which value a maximum gradient color should be used.
		/// </summary>
		public double DataMax
		{
			get
			{
				return dataMax_;
			}
			set
			{
				dataMax_ = value;
			}
		}
		private double dataMax_;


		/// <summary>
		/// Calculates the minimum and maximum values of the data array.
		/// </summary>
		private void calculateMinMax()
		{
			dataMin_ = data_[0,0];
			dataMax_ = data_[0,0];
			for (int i=0; i<data_.GetLength(0); ++i)
			{
				for (int j=0; j<data_.GetLength(1); ++j)
				{
					if (data_[i,j]<dataMin_) 
					{
						dataMin_ = data_[i,j];
					}
					if (data_[i,j]>dataMax_) 
					{
						dataMax_ = data_[i,j];
					}
				}
			}
		}


		/// <summary>
		/// Constructor
		/// </summary>
		/// <param name="data">the 2D array to plot</param>
		/// <param name="xStart">the world value corresponding to the 1st position in the x-direction</param>
		/// <param name="xStep">the world step size between pixels in the x-direction.</param>
		/// <param name="yStart">the world value corresponding to the 1st position in the y-direction</param>
		/// <param name="yStep">the world step size between pixels in the y-direction.</param>
		/// <remarks>no adapters for this yet - when we get some more 2d
		/// plotting functionality, then perhaps create some.</remarks>
		public ImagePlot( double[,] data, double xStart, double xStep, double yStart, double yStep )
		{

#if CHECK_ERRORS
			if (data == null || data.GetLength(0) == 0 || data.GetLength(1) == 0)
			{
				throw new NPlotException( "ERROR: ImagePlot.ImagePlot: Data null, or zero length" );
			}
#endif

			this.data_ = data;
			this.xStart_ = xStart;
			this.xStep_ = xStep;
			this.yStart_ = yStart;
			this.yStep_ = yStep;
			this.calculateMinMax();
		}


		/// <summary>
		/// Constructor
		/// </summary>
		/// <param name="data">The 2D array to plot.</param>
		public ImagePlot( double[,] data )
		{
			this.data_ = data;
			this.calculateMinMax();
		}


		/// <summary>
		/// Draw on to the supplied graphics surface against the supplied axes.
		/// </summary>
		/// <param name="g">The graphics surface on which to draw.</param>
		/// <param name="xAxis">The X-Axis to draw against.</param>
		/// <param name="yAxis">The Y-Axis to draw against.</param>
		/// <remarks>TODO: block positions may be off by a pixel or so. maybe. Re-think calculations</remarks>
		public void Draw( Graphics g, PhysicalAxis xAxis, PhysicalAxis yAxis )
		{
			if ( data_==null || data_.GetLength(0) == 0 || data_.GetLength(1) == 0 )
			{
				return;
			}

			double worldWidth = xAxis.Axis.WorldMax - xAxis.Axis.WorldMin;
			double numBlocksHorizontal = worldWidth / this.xStep_;
			double worldHeight = yAxis.Axis.WorldMax - yAxis.Axis.WorldMin;
			double numBlocksVertical = worldHeight / this.yStep_;

			double physicalWidth = xAxis.PhysicalMax.X - xAxis.PhysicalMin.X;
			double blockWidth = physicalWidth / numBlocksHorizontal;
			bool wPositive = true;
			if (blockWidth < 0.0)
			{
				wPositive = false;
			}
			blockWidth = Math.Abs(blockWidth)+1;

			double physicalHeight = yAxis.PhysicalMax.Y - yAxis.PhysicalMin.Y;
			double blockHeight = physicalHeight / numBlocksVertical;
			bool hPositive = true;
			if (blockHeight < 0.0)
			{
				hPositive = false;
			}
			blockHeight = Math.Abs(blockHeight)+1;

			for (int i=0; i<data_.GetLength(0); ++i)
			{
				for (int j=0; j<data_.GetLength(1); ++j)
				{
					double wX = (double)j*this.xStep_ + xStart_;
					double wY = (double)i*this.yStep_ + yStart_;
					if ( !hPositive )
					{
						wY += yStep_;
					}
					if (!wPositive )
					{
						wX += xStep_;
					}

					if (this.center_)
					{
						wX -= this.xStep_/2.0;
						wY -= this.yStep_/2.0;
					}
					Pen p = new Pen( this.Gradient.GetColor( (data_[i,j]-this.dataMin_)/(this.dataMax_-this.dataMin_) ) );
					int x = (int)xAxis.WorldToPhysical(wX,false).X;
					int y = (int)yAxis.WorldToPhysical(wY,false).Y;
					g.FillRectangle( p.Brush,
						x,
						y, 
						(int)blockWidth,
						(int)blockHeight);
					//g.DrawRectangle(Pens.White,x,y,(int)blockWidth,(int)blockHeight);
				}
			}
		}


		/// <summary>
		/// The gradient that specifies the mapping between value and color.
		/// </summary>
		/// <remarks>memory allocation in get may be inefficient.</remarks>
		public IGradient Gradient
		{
			get
			{
				if (gradient_ == null)
				{
					// TODO: suboptimal.
					gradient_ = new LinearGradient( Color.FromArgb(255,255,255), Color.FromArgb(0,0,0) );
				}
				return this.gradient_;
			}
			set
			{
				this.gradient_ = value;
			}
		}
		private IGradient gradient_;


		/// <summary>
		/// Draws a representation of this plot in the legend.
		/// </summary>
		/// <param name="g">The graphics surface on which to draw.</param>
		/// <param name="startEnd">A rectangle specifying the bounds of the area in the legend set aside for drawing.</param>
		public void DrawInLegend( Graphics g, Rectangle startEnd )
		{
			// not implemented yet.
		}


		/// <summary>
		/// A label to associate with the plot - used in the legend.
		/// </summary>
		public string Label
		{
			get
			{
				return label_;
			}
			set
			{
				this.label_ = value;
			}
		}
		private string label_ = "";


		/// <summary>
		/// Returns an x-axis that is suitable for drawing this plot.
		/// </summary>
		/// <returns>A suitable x-axis.</returns>
		public Axis SuggestXAxis()
		{
			if (this.center_)
			{
				return new LinearAxis( this.xStart_ - this.xStep_/2.0, this.xStart_ + this.xStep_ * data_.GetLength(1) - this.xStep_/2.0 );
			}
			
			return new LinearAxis( this.xStart_, this.xStart_ + this.xStep_ * data_.GetLength(1) );
		}


		/// <summary>
		/// Returns a y-axis that is suitable for drawing this plot.
		/// </summary>
		/// <returns>A suitable y-axis.</returns>
		public Axis SuggestYAxis()
		{
			if (this.center_)
			{
				return new LinearAxis( this.yStart_ - this.yStep_/2.0, this.yStart_ + this.yStep_ * data_.GetLength(0) - this.yStep_/2.0 );
			}
			
			return new LinearAxis( this.yStart_, this.yStart_ + this.yStep_ * data_.GetLength(0) );
		}


		/// <summary>
		/// If true, pixels are centered on their respective coordinates. If false, they are drawn
		/// between their coordinates and the coordinates of the the next point in each direction.
		/// </summary>
		public bool Center
		{
			set
			{
				center_ = value;
			}
			get
			{
				return center_;
			}
		}
		private bool center_ = true;


		/// <summary>
		/// Whether or not to include an entry for this plot in the legend if it exists.
		/// </summary>
		public bool ShowInLegend
		{
			get
			{
				return showInLegend_;
			}
			set
			{
				this.showInLegend_ = value;
			}
		}
		private bool showInLegend_ = true;


		/// <summary>
		/// Write data associated with the plot as text.
		/// </summary>
		/// <param name="sb">the string builder to write to.</param>
		/// <param name="region">Only write out data in this region if onlyInRegion is true.</param>
		/// <param name="onlyInRegion">If true, only data in region is written, else all data is written.</param>
		/// <remarks>TODO: not implemented.</remarks>
		public void WriteData( System.Text.StringBuilder sb, RectangleD region, bool onlyInRegion )
		{
		}


	}
}
